Bioequivalence of compound chlorzoxazone tablets in healthy volunteers

Objective: To investigate the bioequivalence of compound chlorzoxazone tablets in healthy volunteers.Methods: Single oral doses of two compound chlorzoxazone tablets(chlorzoxazone 500mg and acetaminophen 600mg) were given to 20 male volunteers in an open,randomized and cross-over study.The concentrations of chlorzoxazone and acetaminophen were determined by HPLC,and the pharmacokinetic parameters were calculated with DAS 2.0.Results: The pharmacokinetic parameters of acetaminophen for test and reference tablets were as follows: Cmax,(14.65±4.10) and(16.95±5.14)μg·mL-1;Tmax,(0.8±0.3) and(0.7±0.3)h;AUC0-12,(47.63±13.21) and(48.89±14.43)h·μg·mL-1;t1/2,(2.90±0.99) and(2.82±0.62)h,respectively.The parameters of chlorzoxazone were as follows: Cmax,(18.07±5.07) and(18.30±3.31)μg·mL-1;Tmax,(1.2±0.5) and(1.1±0.4)h;AUC0-8,(43.14±7.33) and(43.90±6.39)h·μg·mL-1;t1/2,(1.09±0.17) and(1.12±0.25)h,respectively.The relative bioavalibility of chlorzoxazone and acetaminophen in compound chlorzoxazone tablets were(109.1±30.9)% and(114.0±50.5)%,respectively.Conclusion: The pharmacokinetic parameters for both test and reference tablets are similar,and two tablets are bioequivalent in healthy volunteers.